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Yes, The small additional step is that before using each day you open/close the valve on the top to equalize the gauge to current atmospheric pressure.
Just a thought in general: It is important to be sure to understand the difference between accuracy and resolution. A lot of gauges out there will claim high resolution, for example claiming that they give readings in 0.1 lb increments. They are not necessarily highly accurate though. Ideally you want a gauge with high accuracy, meaning that the reading is correct in an absolute sense.
The LongAcre gauges are some of the most accurate out there. Likely more accurate than needed for our cars in general use, but why not go for good accuracy when it is available. A good quality gauge will list both its accuracy and its resolution.
Actually since the main reason for checking this at all is to make the car handle and feel the way YOU want, then accuracy hardly matters at all. What do you care, if the car sticks and slides and rides just the way you want, if the tires are 36 psi or "really" 35.5 psi? Unless for some reason you want a really plush ride and find 28 psi perfect, when in reality because your gauge is inaccurate this turns out to be an underinflated 22 psi, what does it matter? It doesn't. So unless the gauge is dramatically off AND SO ARE YOU, accuracy makes no difference. Not just my opinion. Walk around the grid at autocross, see if anyone cares what YOUR guage says THEIR tire pressure is. They don't care AT ALL! All they care about is that having done a zillion timed runs they know exactly what pressure they want to see with their gauge on their tires.
Well, the ones who know what they're doing, anyway.
Resolution, on the other hand, is everything. Once you get to where you know EXACTLY what you want, you want EXACTLY that. Whatever "that" is. Not half a pound more. Not a quarter of a pound less. Exactly "that". Why is this so important? Under ideal straight line threshold braking differences between the left and right side of a fraction of a pound can cause one side or the other to lock a bit early. And that will cost you. So while you almost certainly want several pounds more rear than front you for damn sure want left and right exactly the same. Not accurate to some laboratory standard. Exactly the same as the other side. Whatever that may be. So resolution is everything. Accuracy? Not so much.
And now you know why the most coveted gauges have great big analog dials with lots of space between each fraction of a pound. Because when you know what you're doing, that's what you want.
Given both of them and the TPS monitor agree except for an occasional rounding difference, then I consider that close enough.
I agree.
What do you start with at cold (~60 degrees F)? How much does it go up in the best heat/grip circumstances? Which tire do you have?
I also use a digital heat sensor to test the three thirds of the front tires to be sure that they are giving me the best grip. I try for 180 degrees on all three sections after a street test. So, it's 180 degrees over the tire with a hot pressure of 36 degrees on mountain roads.
Read my earlier post about resolution. Resolution has little to do with accuracy. You just used the two words interchangeably and they are not.
Nonetheless, the gauge you mention does have an astounding accuracy 0.1% according to their website. But that degree of accuracy isn't needed for 99.9% of us. I guess that's what the $290 dollars gets you on the Intercomp.
The LongAcre has a mere 2% accuracy, max 1.0psi error at 50psi, max 0.5psi at 25psi. That's close enough for me. And I thought I had splurged with my $55 LongAcre!
Actually since the main reason for checking this at all is to make the car handle and feel the way YOU want, then accuracy hardly matters at all. What do you care, if the car sticks and slides and rides just the way you want, if the tires are 36 psi or "really" 35.5 psi? Unless for some reason you want a really plush ride and find 28 psi perfect, when in reality because your gauge is inaccurate this turns out to be an underinflated 22 psi, what does it matter? It doesn't. So unless the gauge is dramatically off AND SO ARE YOU, accuracy makes no difference. Not just my opinion. Walk around the grid at autocross, see if anyone cares what YOUR guage says THEIR tire pressure is. They don't care AT ALL! All they care about is that having done a zillion timed runs they know exactly what pressure they want to see with their gauge on their tires.
Well, the ones who know what they're doing, anyway.
Resolution, on the other hand, is everything. Once you get to where you know EXACTLY what you want, you want EXACTLY that. Whatever "that" is. Not half a pound more. Not a quarter of a pound less. Exactly "that". Why is this so important? Under ideal straight line threshold braking differences between the left and right side of a fraction of a pound can cause one side or the other to lock a bit early. And that will cost you. So while you almost certainly want several pounds more rear than front you for damn sure want left and right exactly the same. Not accurate to some laboratory standard. Exactly the same as the other side. Whatever that may be. So resolution is everything. Accuracy? Not so much.
And now you know why the most coveted gauges have great big analog dials with lots of space between each fraction of a pound. Because when you know what you're doing, that's what you want.
I completely agree with you... I was just saying that if I'm going to drop $50 on a nice solid gauge I'd just prefer that it also be reasonably accurate. I personally like the LongAcre mostly because I can slightly overfill the tire then use the bleed valve on the gauge to get to the reading I want. I also like the solid feel and rubberized edges. The bleed valve on my prior cheap gauge failed within a year.
When I autocross there is no one magic number that I must absolutely hit... maybe I'm just not that good. I just like all of the tires to be the same left to right and in right ballpark for what I'm expecting.
Like MikeCanPlay stated in the first response, the simplest way to get the pressure where you want regardless of temperature is just to use the Fill Info mode on the MFD which uses the tire temperature in its calcuatiopns to tell you have much you need to adjust the tire for whatever the current tire temperature is. I tend to use this, but don't always go for 0 in Comfort Mode. I'm fine with fairly small negative readings here, as long as I'm getting the same reading side-to-side.
Read my earlier post about resolution. Resolution has little to do with accuracy. You just used the two words interchangeably and they are not.
Nonetheless, the gauge you mention does have an astounding accuracy 0.1% according to their website. But that degree of accuracy isn't needed for 99.9% of us. I guess that's what the $290 dollars gets you on the Intercomp.
The LongAcre has a mere 2% accuracy, max 1.0psi error at 50psi, max 0.5psi at 25psi. That's close enough for me. And I thought I had splurged with my $55 LongAcre!
The poster poses a question regarding accuracy between analogue and digital gauges as to which is more accurate. That's why I use Intercomp's 1/100 psi resolution as an example of how accurate a digital gauge and achieve. Now whether you need it or not is a different issue. Some people are quite happy with a plunger pencil pressure gauge that they might be happy with its 20% accuracy, while there are people who wants their gauge to be no less than 3%, or even .001 % as the Intercomp.
I prefer this one because of the quick attach/release mechanism and the fill port which lets you monitor the air pressure as you add air. I've purchased 4 of these, one for every car I own and another as a gift, and all have operated with nice, consistent quality.
The poster poses a question regarding accuracy between analogue and digital gauges as to which is more accurate. That's why I use Intercomp's 1/100 psi resolution as an example of how accurate a digital gauge and achieve. Now whether you need it or not is a different issue. Some people are quite happy with a plunger pencil pressure gauge that they might be happy with its 20% accuracy, while there are people who wants their gauge to be no less than 3%, or even .001 % as the Intercomp.
Oops. I misread the question Porsche_nuts asked earlier about water-filled vs digital gauges... somehow I thought he was referring to basic needle-based gauges. Sorry about that Porsche_nuts, I amended that answer. The liquid-filled gauges are only more accurate than that ones that aren't liquid filled, and then by only a little. High-end digital gauges are more accurate than either of those.
henryting, I understand your point. My attempted point was really a terminology technicality. I was trying to point out that a device can have high resolution and still not be accurate. You see that in a lot of ultra-cheap devices declaring readings to 0.1psi for example (even if that reading might be off by several psi). However, accurate devices will have always have good-enough resolution to be, well... accurate.
I have two, one in each vehicle - and they read the same. The swivel chuck is nice and and the reverse orientation of the dial has really turned out to be a plus.
As I recall, the last time I filled up I compared the car display to my tire gauge. Ignition on and TPMS. Wheels do not need to be rolling nor engine running. Display matched my fancy gauge almost exactly and in real time. Save your money.
DK. On my 17 911S, I get a message that the TPMS are displayed @ 15 MPH? I can view them unless I'm rolling.
02-27-2018, 07:04 PM
